If your period is 10 days late, you should go ahead and take a test now. There are even some tests out there now that can tell you if you're pregnant up to 4 days before your period is due.
I have 3 kids and with 2 of them, my period was a couple days late so I tested and with my third, I found out about a week before my period was due. I wasn't even a month along.
Rest In Peace, Laci & Connor.
May God Embrace Your Souls & Bring Your Family Peace.